1. Technical Field
The present invention relates to a charging element device equipped in electric cars, hybrid electric cars, and the like, as a driving power supply. The invention relates to any type of charging element device, including cells such as nickel hydrogen battery and lithium batteries and energy storage devices such as double layered capacitors (ultra-capacitors).
2. Background Art
As this type of charging element device, a conventional one is known in which plural cylindrical cells are connected to each other to construct a columnar battery module. The plural cylindrical battery modules are laterally aligned in parallel to form an array, and the plural arrays are built-up. All the battery modules are serially connected to each other to generate high-voltage power. For example, Japanese Patent Application, First Publication, No. 10-270006 discloses a charging element device contained in a housing, in which battery modules are aligned in three rows, which are built-up in seven stages. Each battery module passes through holes which are provided in end walls of the housing and partitions provided in the housing, and is secured in the alignment by fitting opposite terminals thereof into resin endplates mounted on the end walls. The charging element device copes with large amounts of heat by blowing cooling air in the built-up direction (vertical direction) through the spaces divided by the partitions toward the axial direction of the battery modules.
In the battery module, the terminal is fitted into the endplate, and adjoining terminals are connected and secured by a bus bar plate, whereby the ends of the battery module are rigidly secured. In contrast, the intermediate portion of the battery module has a clearance with the circumference of the hole, and this result in vibration and bending of the battery module. Therefore, the proposed device is designed such that a rubber cushion is laminated over the partition, a cushioning ring is formed integrally with the rubber cushion, and the battery module is passed through the cushioning ring so as to hold the intermediate portion of the battery module and to restrain vibration and bending thereof.
In the design in which the battery module is aligned so as to pass through the holes provided in the end walls and partitions, the holes must be larger than the outer diameter of the battery module even though the clearance is small, and vibration and bending thereof are therefore inevitable. Although the cushioning ring as the above description holds the intermediate portion of the battery, it is not in a fixed condition and is not completely restrained, so that vibration and bending occur due to vibration and impacts during the running of a vehicle. When the vibration and bending occurring in the battery module are large, the load exerted on the fixed portion of the endplate may increase, and problems such as breaking of the endplate or loosening of the fixed portion may occur. Therefore, the strength of the fixing and the endplate itself must be increased, thereby increasing the total weight of the device.
Furthermore, in the design for cooling as in the above description, since cooling air flows during contact with the battery module, although the inlet portion may be cooled by the cooling air, the cooling effect may diminish as the distance therefrom increases. Therefore, the temperatures of the battery modules are different from each other, and this results in shortening of the service life of the device and decreases in performance in which charging and discharging are efficiently repeated.
Therefore, an object of the present invention is to provide the following charging element devices. In a charging element device constructed by assembling plural charging elements or battery modules, vibration and bending can be effectively restrained and load exerted on securing portions at opposite ends can be reduced, thereby increasing the securing strength and achieving weight reduction. Moreover, all charging elements can be cooled sufficiently and evenly, the charging and discharging efficiency and the service life can be increased.
The first aspect of the invention provides a charging element device comprising: columnar charging element modules arranged by serially connecting cylindrical cells via an insulating ring, the module having a terminal at opposite ends thereof; charging element module groups arranged by laterally aligning the charging element modules in parallel; a built-up construction of the charging element modules arranged by building-up the charging element module groups in several stages; bus bar plates disposed at the opposite ends of the built-up construction of charging element modules and fitted to the terminals; bus bars disposed outside the bus bar plate and serially connecting the terminals; a housing in which cooling air flows and the built-up construction of the charging element modules is contained; and mounting plates having a securing ring for holding and securing the insulating ring, the mounting plate being provided below the lowermost charging element module group, above the uppermost charging element module group, and between the intermediate charging element module groups; wherein the mounting plates are integrally bound so as to hold and secure the insulating ring by the securing ribs; a restriction arrangement for rotation of the insulating ring is provided to the insulating ring and the securing rib.
According to the invention, the insulating ring held by the cells is held and secured by the securing ribs of the mounting plates, so that the intermediate portion of the charging element module is supported by the mounting plates. Therefore, vibration and bending of the module are restrained, and the load exerted on the opposite securing portions of the bus bar plates is reduced. As a result, the securing strength is increased and the weight of the charging element module is reduced. Furthermore, the rotation of the insulating ring is restricted, so that the necessary securing strength for the insulating ring by the mounting plates can be reduced, and the weight can be further reduced.
According to a preferred embodiment of the invention, the mounting plate includes rectifying plates disposed between the charging element modules and extending along an axial direction of the charging element modules, whereby cooling air passes through the interval of the rectifying plates and flows in the built-up direction of the charging element modules. The built-up construction of charging element modules has an upper surface and a lower surface, one of which serves as a cooling air inlet surface, the built-up construction of charging element modules is inclined so that the cooling air inlet surface faces toward the upstream of the cooling air.
The rectifying plates are provided to the mounting plate so that the both elements can be integrally formed, and the assembly can be simplified and assembling efficiency can be increased. By inclining the built-up construction of charging element modules, fresh cooling air comes directly into contact with the entire surface of a cooling air inlet surface provided to the built-up construction of charging element modules, the cooling air flows from the inlet surface toward the built-up direction of the built-up construction of charging element modules during passing through the rectifying plates. Therefore, the flow rate and the flow velocity of the cooling air flowing the axial direction and the built-up direction of each charging element module can be even, and as a result, the charging element modules are evenly cooled and the charging and discharging efficiency and the service life thereof can be increased.
It should be noted that the number of the stages of the charging element module groups may be less than the number of the charging element modules comprising the charging element module group. Such an arrangement can promote the cooling efficiency and reduce the number of the mounting plates.
In order to avoid misassembly in connecting terminals with different polarities by the bus bar, the following arrangements are preferable.
The charging element module may have opposite polarities in the terminals, four protrusions are formed along a concentric circle on the terminals, an end of the bus bar is fitted into the inside of the protrusions, the phase of the protrusions on the terminal with the polarity is offset from the phase of the protrusions on the terminal with the other polarity, so that one protrusion is positioned at an extending portion of the bus bar. The diameters of the concentric circles may be different from each other. The bus bar may include a hole which receives one protrusion so as to allow the connection of the terminals by the bus bar.
By the above arrangements, the bus bar can be fitted to only the regular terminals, so that misassembly can be completely avoided. The protrusion supports the torque and serves as a stopper against the rotation when the bus bar is secured by a bolt, and the operation efficiency thereof can be increased.
Another aspect of the invention provides a charging element device comprising: columnar charging element modules arranged by serially connecting cylindrical cells via an insulating ring, the module having a terminal at opposite ends thereof; charging element module groups arranged by laterally aligning the charging element modules in parallel; bus bar plates disposed at the opposite ends of the built-up construction of charging element modules and fitted to the terminals; bus bars disposed outside the bus bar plate and serially connecting the terminals; a housing in which cooling air flows and the built-up construction of the charging element modules is contained; and mounting plates disposed apart from each other in an axial direction of the charging element module, the mounting plates being arranged such that the charging element modules are inserted thereinto and are circumferentially aligned to form the charging element module group; holding and securing the insulating ring, the mounting plate being provided below the lowermost charging element module group, above the uppermost charging element module group, and between the intermediate charging element module groups; a cooling air path disposed in a radially inner portion or a radially outer portion of the charging element module group; wherein the mounting plate has securing ribs for fitting and securing the insulating rings, and a restriction arrangement for rotation of the insulating ring is provided to the insulating ring and the securing rib.
According to the invention, cooling air flows in the radial inside or outside of the charging element module group which is circumferentially aligned, so that the fresh cooling air can contact along the entire length of the charging element modules. Therefore, the charging element modules are evenly cooled, and the charging and discharging efficiency and the service life can be increased.
Moreover, the insulating ring held by the cells is fitted and secured by the securing ribs of the mounting plates, so that the intermediate portion of the charging element module is supported by the mounting plates. Therefore, vibration and bending of the module are restrained, and the load exerted on the opposite securing portions of the bus bar plates is reduced. As a result, the securing strength is increased and the weight of the charging element module is reduced. Furthermore, the rotation of the insulating ring is restricted, so that the necessary securing strength for the insulating ring by the mounting plates can be reduced, and the weight can be further reduced.
In the invention, in order to circumferentially align and connect the terminals by bus bars and to avoid misassembly in connecting the terminals by the bus bar, the following arrangements are preferable.
The charging element module may have opposite polarities in the terminals, and four protrusions may be formed along a concentric circle on the terminals. An end of the bus bar may be fitted into the inside of the protrusions, the phase of the protrusions on the terminal with the polarity may be offset by Kxc2x0 which is calculated by the following equation (1) in which the number of the charging element modules is defined as xe2x80x9cHxe2x80x9d, from the phase of the protrusions on the terminal with the other polarity, so that one protrusion is positioned at an extending portion of the bus bar.
360/H=Kxe2x80x83xe2x80x83(1)
The diameters of the concentric circles may be different from each other. Furthermore, the bus bar may include a hole which receives the one protrusion so as to allow the connection of the terminals by the bus bar. On the other hand, the bus bar may be formed with a hole into which the protrusion is fitted to allow connecting of the terminals by the bus bar.
Preferred embodiments which can be applied to the first and second aspects of the invention will be explained hereinafter.
The device may comprise a connecting ring serially connecting the charging elements, the connecting ring is fitted to the insulating ring and an outer package of the charging element, which has one polarity thereof, and contacts the other charging element. The connecting ring and the insulating ring may have a positioning arrangement for circumferentially positioning the relative location thereof The insulating ring may cover at least a portion of an outer surface of the connecting ring.
In a charging element module, the designs of the terminals with different polarities will usually be differed from each other to avoid misassembly in which the same polarities are connected. In the above embodiment, by connecting the charging elements during positioning the insulating ring and the connecting ring by the positioning arrangement, a charging element module in which the relative circumferential positions of the opposite terminals are constant can be formed. By using such charging element modules, the bus bar can be smoothly fitted to the terminals. Moreover, the insulating ring covering at least a portion of the outer surface of the connecting ring radially projects from the connecting ring. Therefore, the securing rib and the mounting plates can be formed from non-insulating materials, and materials having superior strength-weight ratios and rigidity-weight ratios, such as high-strength magnesium alloys and high-rigidity aluminum alloys, can be used, so that the weight can be further reduced.
The charging element module may have opposite polarities in the terminals, the terminal with one polarity may have a cross section different from that of the terminal with the other polarity, and the terminal may have a connecting portion at the center thereof. The bus bar plate may have holes for corresponding and fitting to the terminals, and the bus bar plate may be assembled with the charging element modules by corresponding and fitting the holes to the terminals.
In the charging element device of the invention, a pair of terminals with different polarities of adjoined charging element modules are serially connected. By forming the terminals into protruded shapes with different cross sections, the difference can be easily distinguished, so that misconnection in which the same polarities are connected can be prevented. By forming holes corresponding the terminals in the bus bar plates and fitting the terminals thereto, misconnection of the bus bar plate can be avoided and the assembly can smoothly performed.
In order to form the cross sections of the terminals with different polarities, the positive terminal and the negative terminal may have a cross section with approximately a star-shape or a circular cross section. By this arrangement, the difference of the polarities is apparent and can be easily distinguished.